Most American children fall short of ideal heart health, a new American Heart Association scientific statement says.

An analysis of 2007-08 federal government survey results found that about 91 percent of youngsters did not have healthy diets. Those between the ages of 2 and 19 get most of their calories from simple carbohydrates such as sugary drinks and desserts.

"A primary reason for so few children having ideal cardiovascular health is poor nutrition," statement author Dr. Julia Steinberger said in an association news release. "Children are eating high-calorie, low-nutrition foods and not eating enough healthy foods, such as fruits, vegetables, whole-grains, fish and other foods strongly associated with good heart health and a healthy body weight."

Lack of physical activity is another concern. Among 6- to 11-year-olds, half of boys and about a third of girls got the recommended 60 minutes or more a day of exercise. Between 16 and 19 years of age, those percentages plummeted to 10 percent of boys and 5 percent of girls.

Not surprisingly, kids have packed on the pounds. About 10 percent of 2- to 5-year-olds were obese, compared to between 19 percent and 27 percent of 12- to 19-year olds. About a third of the older kids had tried a cigarette.

Nearly all the children had ideal blood pressure. And most had ideal cholesterol and blood sugar levels, though not as good as blood pressure levels, according to the statement published Aug. 11 in the journal Circulation.

Overall, the findings show that instead "of taking a wait-and-see approach by treating disease later in adulthood, we should help children maintain the standards of ideal cardiovascular health that most children are born with," said Steinberger, director of pediatric cardiology at the University of Minnesota.